An email append, or e-append, is the process in which you obtain email addresses by using public or private demographic data, such as a postal address, that is known or related to one of your subscribers or potential subscribers. Your data is matched to a third party database in order to obtain the email addresses. In most cases, the potential subscriber has not explicitly given you permission or consent to email them directly.
Email appending is considered a poor list acquisition practice in the email industry since it does not involve consent. It may also lead to high complaints, unknown users and hitting spam traps, which can harm your sending reputation and lead to deliverability problems.
Email Glossary
